Question: Khan.scratchpad.disable(); Michael sells magazine subscriptions and earns $$5$ for every new subscriber he signs up. Michael also earns a $$33$ weekly bonus regardless of how many magazine subscriptions he sells. If Michael wants to earn at least $$90$ this week, what is the minimum number of subscriptions he needs to sell?
Solution: To solve this, let's set up an expression to show how much money Michael will make. Amount earned this week $=$ $ $ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus Since Michael wants to make at least $$90$ this week, we can turn this into an inequality. Amount earned this week $\geq $90$ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus $\geq $90$ We are solving for the number of subscriptions sold, so let subscriptions sold be represented by the variable $x$ We can now plug in: $x \cdot $5 + $33 \geq $90$ $ x \cdot $5 \geq $90 - $33 $ $ x \cdot $5 \geq $57 $ $x \geq \dfrac{57}{5} \approx 11.40$ Since Michael cannot sell parts of subscriptions, we round $11.40$ up to $12$ Michael must sell at least 12 subscriptions this week.